The Center uses two different physics curricula in the Detroit Public Schools: Helmet and Simple Machines.
| Why do I need to wear a helmet when I ride my bike? Who hasn't heard a kid ask that question? The Helmet Unit, used in the Detroit Public Schools, helps students understand the value of wearing a helmet while learning physics principles at the same time. The unit teaches such concepts as force, velocity, and acceleration. Students design their own experiments, make predictions and observations, construct hypotheses, analyze and interpret data, and draw conclusions about what happens when a collision occurs. The unit is divided into six sub-questions.  | What happens when I don’t wear my helmet? Students discuss their personal experiences with bikes and falls to put the physics concepts in context. Teachers introduce the concepts of force and motion through a series of experiments involving an egg in a small cart traveling down a ramp riding. Students use this demonstration throughout the curriculum. In this section, students begin to see science as asking and answering a series of questions and then learn how to design experiments to help them do it. | | Why do I get pitched off my bike? The definitions of motion and force help explain how a collision can throw someone off a bike. Further investigation into the relationships between motion and force, between motion and energy conservation, and between mass and energy conservation deepen students’ understanding of force and motion concepts. | | How fast was I going when I got pitched off my bike? In this section, students learn about velocity. Using motion sensors, they experiment with the block, cart, and ramp to understand the concepts of motion and velocity, and constant and changing energy. Students also learn to read and interpret position/time graphs generated by the motion sensors.  | | By raising or lowering the height and angle of the ramp, students make the cart accelerate at different rates, knocking the block forward different distances. |
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| | Why was I going so fast? Students collect data with motion sensors to study velocity, the relationships between motion and velocity, and the concepts of constant and changing velocity. Once again, students use the block, cart, and ramp demonstration for experimentation and data collection. | | Why do I get hurt when I get pitched off my bike? Here, students investigate the concept of force by using force sensors and the cart-and-egg set up to collect data on mass and gravity. Students also begin to focus on interpreting their data and drawing conclusions based on it. The basic concepts covered in this section include action-reaction, mass and force, and acceleration and force. | | Can my helmet keep me from getting hurt? Finally, students bring all these ideas together in an investigation of collisions using motion and force sensors. They then demonstrate their understanding of collisions by creating a helmet for the egg. |
The Helmet Unit incorporates two technologies: computer-based force and motion sensors and Interactive Physics (IP) software. The sensors interface with DataStudio, a data interpretation application available from Pasco. Students use IP to create and run physics simulations to explore concepts like momentum, force, and friction. IP has the capability to graph data as they change over time. The program also includes tools similar to “paint programs” to create sophisticated models of systems. This unit for seventh-graders takes about eight weeks to complete.  | The motion sensor used in the Helmet unit records the position, velocity, and acceleration of the cart and the data are represented graphically onscreen. This graph shows the positions of the cart on three runs, each with a different mass attached to the cart. Click on the thumbnail to see the full-sized screenshot. |
| | This question drives the Simple Machines unit, in which students investigate how simple machines-such as inclined planes, levers, and pulleys-help people build large structures. Through their investigations, students develop an understanding of force and motion, and the trade-off between force and distance that occurs when using simple machines. Because students are investigating how they use machines, they are naturally led to question how machines make their lives easier and how they might design better machines.
In the course of this unit, students visit a construction site, observe demonstrations of balanced and unbalanced force, and investigate the use of force with and without different simple machines. Students also form “construction companies” to design an improved machine for use in building a large structure. The unit consists of five sections: | How Are Big Things Built? Students put this question in context by visiting a construction site and recording their observations of the equipment and activities there. Students are then given a design task. They form small group construction companies, come up with a name for their company, and write a report reflecting what they believe about how people build things, how machines are used, and how they might design a new machine. | | How Do I Move Things? This section introduces the concepts of balanced and unbalanced forces and motion. Through a series of demonstrations using force probes and a bucket of bricks, students explore the relationships between applied force, resisting forces (friction and gravity, for example), and motion. They use these concepts to revise and improve the design of their machines. | | How Do Machines Move Big Things That I Can't? To help them understand mechanical advantage and the trade-off between force and distance, students discuss the differences between machines used to build large structures today and those used long ago to build structures like the Pyramids. Using investigations of inclined planes, levers, and pulleys, they collect and analyze data to draw conclusions about machines. They further refine their own machines' designs based on this information. | | How Can I Change a Machine to Move Bigger Things? In this section, students design their own experiments to help them improve their machines. As inclined plane, lever, and pulley engineers, they will identify the characteristics of their machines that could be changed to make them work better. They will perform investigations to test their ideas. They also explore how to combine simple machines to make more efficient complex machines. | | How Can I Use Machines to Help Me Build Big Things? Finally, students refine and finalize their machine designs based on their research and investigations, and then present their designs to the class. |
Simple Machines uses force sensors and DataStudio software, which are available for the Macintosh and PC platforms. DataStudio is a commercial software package available from Pasco. Please click here for a summary of system requirements. The curriculum designer for this unit is Ann Rivet at the University of Michigan. Please contact her to obtain materials for this curriculum unit. | Home | Top of Page |
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